20101101021 has 20 divisors (see below), whose sum is σ = 30594135132. Its totient is φ = 13147887168.

The previous prime is 20101101001. The next prime is 20101101071. The reversal of 20101101021 is 12010110102.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 9535522500 + 10565578521 = 97650^2 + 102789^2 .

It is not a de Polignac number, because 20101101021 - 2⁷ = 20101100893 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20101100994 and 20101101012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101101001) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2336856 + ... + 2345441.

Almost surely, 2^20101101021 is an apocalyptic number.

It is an amenable number.

20101101021 is a deficient number, since it is larger than the sum of its proper divisors (10493034111).

20101101021 is an equidigital number, since it uses as much as digits as its factorization.

20101101021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4682362 (or 4682353 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 20101101021 its reverse (12010110102), we get a palindrome (32111211123).

The spelling of 20101101021 in words is "twenty billion, one hundred one million, one hundred one thousand, twenty-one".